scholarly journals Temperature, but not excess of glycogen, regulates “in vitro” AMPK activity in muscle samples of steer carcasses

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0229480
Author(s):  
Pablo Strobel ◽  
Alex Galaz ◽  
Franz Villaroel-Espíndola ◽  
Ariel Apaoblaza ◽  
Juan Carlos Slebe ◽  
...  
Keyword(s):  
Muscle Glycogen ◽  
Incubation Temperature ◽  
Maximum Activity ◽  
High Ph ◽  
Glycogen Concentration ◽  
Metabolic Coupling ◽  
Highly Sensitive ◽  
Structural Differences ◽  
Ampk Activity

Postmortem muscle temperature affects the rate of pH decline in a linear manner from 37.5°C to 0–2°C. The pH decline is correlated with the enzymatic degradation of glycogen to lactate and this process includes the metabolic coupling between glycogenolysis and glycolysis, and that are strongly upregulated by the AMPK. In this study, we used 12 samples previously characterized by have different muscle glycogen concentration, lactate and AMPK activity, selected from 38 steers that produced high final pH (>5.9) and normal final pH (<5.8) carcasses at 24 h postmortem. Moreover, we evaluated changes in the AMPK activity in samples from both categories incubated at 37, 25, 17 and 5°C and supplemented with exogenous glycogen. Finally, we analysed if there were structural differences between polymers from both categories. Our results showed that “in vitro” enzymatic AMPK activity evaluated at both 0.5 or 24 h was greater in samples from normal then high pH categories (p <0.01), and in all temperature of incubation analysed (17, 25 and 37°C). For other hand, a greater AMPK activity were obtained in samples incubated at 17 that 25 or 37°C, in normal carcasses at both 0.5 or 24 h (p < 0.01), as also in samples from carcasses categorized as high pH, but at 24 h (p < 0.05). Interestingly, AMPK activity was totally abolished at 5°C, independent of final pH category of carcasses, and was confirmed that the incubation temperature at which the maximum activity was obtained (p < 0.01), at least in carcasses with a normal pH is at 17°C. The enzymatic AMPK activity did not change in relation to excess glycogen (p > 0.05) and we did not detect structural differences in the polymers present in samples from both categories (p > 0.05), suggesting that postmortem AMPK activity may be highly sensitive to temperature and not to in vitro changes in glycogen concentration (p > 0.05). Our results allow concluding that normal concentrations of muscle glycogen immediately at the time of slaughter (0.5 h) and an adequate cooling managing of carcasses are relevant to let an efficient glycogenolytic/glycolytic flow required for lactate accumulation and pH decline, through the postmortem AMPK signalling pathway.

scholarly journals Temperature, but not excess of glycogen, regulate post-mortem AMPK activity in muscle of steer carcasses

2020 ◽  
Author(s):  
P Strobel ◽  
A Galaz ◽  
F Villaroel-Espíndola ◽  
A Apaoblaza ◽  
JC Slebe ◽  
...  
Keyword(s):  
Muscle Glycogen ◽  
Activity Level ◽  
Post Mortem ◽  
High Ph ◽  
Glycogen Concentration ◽  
Highly Sensitive ◽  
Structural Differences ◽  
Ampk Activity ◽  
Rate Of Decline

AbstractPost-mortem muscle temperature affects the rate of decline in pH in a linear manner from 37.5 °C down near 0 °C, and this pH decline is correlated with the enzymatic degradation of glycogen to lactate. This transformation occurs in an anaerobic context that includes the metabolic splice between glycogenolysis and glycolysis; and both processes are strongly upregulated by AMPK enzyme. In this study we reported changes (0.5 h and 24 h post-mortem) in muscle glycogen concentration, lactate and AMPK activity from 12 samples of Longissimus dorsi from 38 steers that produced high pH (>5.9) and normal pH (<5.8) carcasses at 24 h post-mortem. Moreover, we evaluated changes in AMPK activity in samples from both categories incubated at 37, 25, 17 and 5 °C and supplemented with exogenous glycogen. Finally, we analysed if there were structural differences between polymers from both categories. Our analyses show that enzymatic AMPK activity was significantly higher at 17 °C than at 37 °C or 25 °C (p<0.0001 and p<0.05 in samples from normal and high pH categories, respectively), and was near zero at 5 °C. On the other hand, AMPK activity did not change in relation with excess glycogen and we did not detect structural differences in the polymers present in samples from both categories. We concluded that post-mortem AMPK activity level is highly sensitive to temperature and not at in vitro changes in glycogen concentration. Their results suggest that that normal levels of pre-mortem muscle glycogen and an adequate cooling managing of carcasses are relevant to let an efficient glycogenolytic/glycolytic flow required for lactate accumulation and pH decline, trough of post-mortem AMPK signalling pathway.

Effects of high-intensity intermittent swimming on glucose transport in rat epitrochlearis muscle

1998 ◽  
Vol 84 (6) ◽  
pp. 1852-1857 ◽  
Author(s):  
Kentaro Kawanaka ◽  
Izumi Tabata ◽  
Ayumi Tanaka ◽  
Mitsuru Higuchi
Keyword(s):  
Glucose Transport ◽  
Muscle Glycogen ◽  
High Intensity ◽  
Significant Negative Correlation ◽  
Exercise Duration ◽  
Male Rats ◽  
Glycogen Concentration ◽  
Exercise Induced ◽  
Muscle Glycogen Concentration

Recently (K. Kawanaka, I. Tabata, and M. Higuchi. J. Appl. Physiol. 83: 429–433, 1997), we demonstrated that glucose transport activity after repeated 10-s-long in vitro tetani in rat epitrochlearis (Epi) muscle was negatively correlated with the postcontraction muscle glycogen concentration. Therefore, we examined whether high-intensity intermittent swimming, which depletes muscle glycogen to a lower level than that observed after ten 10-s-long in vitro tetani, elicits higher glucose transport than that observed after ten 10-s-long in vitro tetani, which has been regarded as the exercise-induced maximal stimulus for glucose transport. In male rats, 2-deoxy-d-glucose transport rate in Epi muscle after eight bouts of high-intensity intermittent swimming with a weight equal to 18% of body mass (exercise duration: 20 s, rest duration between exercise bouts: 40 s) was higher than that observed after the ten 10-s-long tetani (2.25 ± 0.08 vs. 1.02 ± 0.16 μmol ⋅ ml intracellular water−1 ⋅ 20 min−1). Muscle glycogen concentration in Epi after eight bouts of high-intensity intermittent swimming was significantly lower than that observed after ten 10-s-long in vitro tetani (7.6 ± 0.5 vs. 14.8 ± 1.4 μmol glucose/g muscle). These observations show that the high-intensity intermittent swimming increases glucose transport in rat Epi to a much higher level than that induced by ten 10-s-long in vitro tetani, which has been regarded as the exercise-related maximal stimulus for glucose transport. Furthermore, this finding suggests that the lower muscle glycogen level after high-intensity intermittent swimming than after in vitro tetani may play a role, because there was a significant negative correlation between glucose transport and muscle glycogen concentration in Epi after high-intensity swimming and in vitro tetani.

Synthesis, Antimalarial Evaluation and SAR Study of Some 1,3,5-Trisubstituted Pyrazoline Derivatives

2019 ◽  
Vol 16 (10) ◽  
pp. 807-817 ◽  
Author(s):  
Shilpy Aggarwal ◽  
Deepika Paliwal ◽  
Dhirender Kaushik ◽  
Girish Kumar Gupta ◽  
Ajay Kumar
Keyword(s):  
Antimalarial Activity ◽  
Analysis Data ◽  
Docking Study ◽  
Maximum Activity ◽  
Elemental Analysis Data ◽  
Mass Spectral ◽  
Structure Activity ◽  
Pharmacokinetic Properties ◽  
Sar Study

The synthesis of a novel series of 1,3,5-trisubstitiuted pyrazoline was achieved by refluxing chalcone derivative with different heteroaryl hydrazines. The newly synthesized compounds were characterized by 1H NMR, 13CNMR, mass spectral and elemental analysis data. The synthetic series of novel pyrazoline hybrids was screened for in vitro schizont maturation assay against chloroquine sensitive 3D7 strain of Plasmodium falciparum. Most of the compounds showed promising in vitro antimalarial activity against CQ sensitive strain. The preliminary structure-activity relationship study showed that quinoline substituted analog at position N-1 showed maximum activity followed by benzothiazole substitution, while phenyl substitution lowers the antimalarial activity. The observed activity was persistent by the docking study on P. falciparum cystein protease falcipain-2. The pharmacokinetic properties were also studied using ADME prediction.

scholarly journals Computational Design of a Molecularly Imprinted Polymer for the Biomonitoring of the Organophosphorous Metabolite Chlorferron

Biosensors ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 192
Author(s):  
Bakhtiyar Qader ◽  
Issam Hussain ◽  
Mark Baron ◽  
Rebeca Jiménez-Pérez ◽  
Guzmán Gil-Ramírez ◽  
...  
Keyword(s):  
Biological Samples ◽  
Limit Of Detection ◽  
Computational Design ◽  
Signal Change ◽  
Highly Sensitive ◽  
Limit Of Quantitation ◽  
Molecularly Imprinting Polymers ◽  
Mip Sensor ◽  
Parasitic Mites

Coumaphos is an organophosphorus compound used as insecticide and frequently used by beekeepers for the management of parasitic mites. The most important metabolite, chlorferron (CFN), has been identified in biological samples and foodstuff. The need to quickly identify the presence of typical metabolites, as an indication of interaction with coumaphos has driven the need to produce a highly sensitive electrochemical method for chlorferron analysis, based on molecularly imprinting polymers (MIP) technology. It showed irreversible behaviour with mixed diffusion/adsorption-controlled reactions at the electrode surface. A monoelectronic mechanism of reaction for oxidation has also been suggested. The linear range observed was from 0.158 to 75 µM. Median precision in terms of %RSD around 3% was also observed. For DPV, the limit of detection (LOD) and the limit of quantitation (LOQ) for the CFN-MIP were 0.158 µM and 0.48 µM, respectively. The obtained median % recovery was around 98%. The results were also validated to reference values obtained using GC-MS. Urine and human synthetic plasma spiked with CFN were used to demonstrate the usability of the method in biological samples, showing the potential for biomonitoring. The developed imprinted sensor showed maximum signal change less than 16.8% when related metabolites or pesticide were added to the mix, suggesting high selectivity of the MIP sensor toward CFN molecules. The results from in vitro metabolism of CMP analysed also demonstrates the potential for detection and quantification of CFN in environmental samples. The newly developed CFN-MIP sensor offers similar LoDs than chromatographic methods with shorter analysis time.

scholarly journals GC-MS Based Identification of the Volatile Components of Six Astragalus Species from Uzbekistan and Their Biological Activity

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 124
Author(s):  
Haidy A. Gad ◽  
Nilufar Z. Mamadalieva ◽  
Stefan Böhmdorfer ◽  
Thomas Rosenau ◽  
Gokhan Zengin ◽  
...  
Keyword(s):  
Radical Scavenging ◽  
Reducing Power ◽  
Principal Component ◽  
Inhibitory Effect ◽  
Maximum Activity ◽  
Volatile Components ◽  
Drug Candidates ◽  
Predominant Component ◽  
Clear Differentiation

The compositions of volatile components in the aerial parts of six Astragalus species, namely A. campylotrichus (Aca), A. chiwensis (Ach), A. lehmannianus (Ale), A. macronyx (Ama), A. mucidus (Amu) and A. sieversianus (Asi), were investigated using gas chromatograph-mass spectrometry (GC-MS) analysis. Ninety-seven metabolites were identified, accounting for 73.28, 87.03, 74.38, 87.93, 85.83, and 91.39% of Aca, Ach, Ale, Ama, Amu and Asi whole oils, respectively. Sylvestrene was the most predominant component in Asi, Amu and Ama, with highest concentration in Asi (64.64%). In addition, (E)-2-hexenal was present in a high percentage in both Ale and Ach (9.97 and 10.1%, respectively). GC-MS based metabolites were subjected to principal component analysis (PCA) and hierarchal cluster analysis (HCA) to explore the correlations between the six species. The PCA score plot displayed clear differentiation of all Astragalus species and a high correlation between the Amu and Ama species. The antioxidant activity was evaluated in vitro using various assays, phosphomolybdenum (PM), 2,2 diphenyl-1-picryl-hydrazyl-hydrate (DPPH), 2,2-azino bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), cupric reducing antioxidant capacity (CUPRAC), ferric reducing power (FRAP) and ferrous ion chelation (FIC) assays. In addition, the potential for the volatile samples to inhibit both acetyl/butyrylcholinesterases (AChE, BChE), α- amylase, α-glucosidase and tyrosinase was assessed. Most of the species showed considerable antioxidant potential in the performed assays. In the DPPH assay, Ama exhibited the maximum activity (24.12 ± 2.24 mg TE/g sample), and the volatiles from Amu exhibited the highest activity (91.54 mgTE/g oil) in the ABTS radical scavenging assay. The effect was more evident in both CUPRAC and FRAP assays, where both Ale and Ama showed the strongest activity in comparison with the other tested species (84.06, 80.28 mgTE/g oil for CUPRAC and 49.47, 49.02 mgTE/g oil for FRAP, respectively). Asi demonstrated the strongest AChE (4.55 mg GALAE/g oil) and BChE (3.61 mg GALAE/g oil) inhibitory effect. Furthermore, the best tyrosinase inhibitory potential was observed for Ale (138.42 mg KAE/g). Accordingly, Astragalus species can be utilized as promising natural sources for many medicinally important components that could be tested as drug candidates for treating illnesses such as Alzheimer’s disease, diabetes mellitus and oxidative stress-related diseases.

scholarly journals Nanoimprinted multifunctional nanoprobes for a homogeneous immunoassay in a top-down fabrication approach

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hubert Brueckl ◽  
Astrit Shoshi ◽  
Stefan Schrittwieser ◽  
Barbara Schmid ◽  
Pia Schneeweiss ◽  
...  
Keyword(s):  
Thin Film ◽  
Nanoimprint Lithography ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
In Vitro Diagnostics ◽  
Top Down ◽  
Highly Sensitive ◽  
Optical And Magnetic Properties ◽  
Lift Off

AbstractMultifunctional nanoparticles are discussed as versatile probes for homogeneous immunoassays for in-vitro diagnostics. Top-down fabrication allows to combine and tailor magnetic and plasmonic anisotropic properties. The combination of nanoimprint lithography, thin film deposition, and lift-off processing provides a top-down fabrication platform, which is both flexible and reliable. Here, we discuss the material compositions and geometrical designs of monodisperse multicomponent nanoparticles and their consequences on optical and magnetic properties. The rotational hydrodynamics of nanoparticles is measured and considered under the influence of magnetic shape anisotropy in the framework of the Stoner-Wohlfarth theory. The plasmon-optical properties are explained by discrete-dipole finite-element simulations. Rotational dynamical measurements of imprinted nanoprobes for two test proteins demonstrate the applicability as highly sensitive biomolecular nanoprobes.

scholarly journals Bioprocess development for enhanced endoglucanase production by newly isolated bacteria, purification, characterization and in-vitro efficacy as anti-biofilm of Pseudomonas aeruginosa

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Atef M. Ibrahim ◽  
Ragaa A. Hamouda ◽  
Noura El-Ahmady El-Naggar ◽  
Fatma M. Al-Shakankery
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Yeast Extract ◽  
Statistical Design ◽  
Life Time ◽  
Maximum Activity ◽  
Bioprocess Development ◽  
Ammonium Sulfate Precipitation ◽  
Face Centered ◽  
Central Composite

AbstractEndoglucanase producing bacteria were isolated from Egyptian soils and the most active bacterial strain was identified as Bacillus subtilis strain Fatma/1. Plackett–Burman statistical design was carried out to assess the effect of seven process variables on endoglucanase production. Carboxymethyl cellulose (CMC), yeast extract and peptone were the most significant variables that enhanced the endoglucanase production and thus were selected for further optimization using face-centered central composite design. The highest yield of endoglucanase (32.37 U/mL) was obtained in run no. 9, using 18 g/L CMC, 8 g/L peptone, 7 g/L yeast extract and 0.1 g/L FeSO4.7H2O. The optimized medium showed about eightfold increase in endoglucanase production compared to the unoptimized medium. The produced crude enzyme was further purified by ammonium sulfate precipitation, then DEAE-Sepharose CL6B column. The purified enzyme was shown to have a molecular weight of 37 kDa. The enzyme showed maximum activity at pH 8.0, temperature of 50 °C, incubation time of 60 min. The half-life time (T1/2) was 139.53 min at 50 °C, while being 82.67 min at 60 °C. Endoglucanase at concentration of 12 U/mL effectively removed 84.61% of biofilm matrix of Pseudomonas aeruginosa with marked reduction in carbohydrate content of the biofilm from 63.4 to 7.9 μg.

scholarly journals Innovative and Highly Sensitive Detection of Clostridium perfringens Enterotoxin Based on Receptor Interaction and Monoclonal Antibodies

Toxins ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 266
Author(s):  
Thea Neumann ◽  
Maren Krüger ◽  
Jasmin Weisemann ◽  
Stefan Mahrhold ◽  
Daniel Stern ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Clostridium Perfringens ◽  
Food Poisoning ◽  
Receptor Interaction ◽  
Clostridium Perfringens Enterotoxin ◽  
Fast Detection ◽  
Highly Sensitive ◽  
Basic And Applied Research ◽  
Highly Sensitive Detection

Clostridium perfringens enterotoxin (CPE) regularly causes food poisoning and antibiotic-associated diarrhea; therefore, reliable toxin detection is crucial. To this aim, we explored stationary and mobile strategies to detect CPE either exclusively by monoclonal antibodies (mAbs) or, alternatively, by toxin-enrichment via the cellular receptor of CPE, claudin-4, and mAb detection. Among the newly generated mAbs, we identified nine CPE-specific mAbs targeting five distinct epitopes, among them mAbs recognizing CPE bound to claudin-4 or neutralizing CPE activity in vitro. In surface plasmon resonance experiments, all mAbs and claudin-4 revealed excellent affinities towards CPE, ranging from 0.05 to 2.3 nM. Integrated into sandwich enzyme-linked immunosorbent assays (ELISAs), the most sensitive mAb/mAb and claudin-4/mAb combinations achieved similar detection limits of 0.3 pg/mL and 1.0 pg/mL, respectively, specifically detecting recombinant CPE from spiked feces and native CPE from 30 different C. perfringens culture supernatants. The implementation of mAb- and receptor-based ELISAs into a mobile detection platform enabled the fast detection of CPE, which will be helpful in clinical laboratories to diagnose diarrhea of assumed bacterial origin. In conclusion, we successfully employed an endogenous receptor and novel high affinity mAbs for highly sensitive and specific CPE-detection. These tools will be useful for both basic and applied research.

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